High intensity lamp

ABSTRACT

A high intensity lighting device ( 2 ) is provided. The lighting device has a linear light source ( 4 ), a reflective member ( 6 ), and a translucent region ( 14 ). The linear light source and reflective member typically share a common axis. The reflective member, which can take many shapes, causes light which would normally be absorbed or propagated within a light housing ( 8 ) to converge on the translucent region. The translucent region having a longitudinal axis coincident to the common axis focuses rays of light to an intended area. If desired, a lens ( 44 ) may also be used to collimate the light such as a cylindrical lens or one or more prisms ( 50 ) for example.

This application claims the benefit of Provisional application Ser. No.60/145,326, filed Jul. 23, 1999.

BACKGROUND OF THE INVENTION

The present invention relates to lighting devices, and moreparticularly, to illumination devices adapted to provide high intensitylighting.

A known problem with using typical prior art lights in high intensityapplications is that the lights consume large quantities of power andgenerate excessive heat in comparison to other lighting devices. Theseapplications thereby suffer not only from higher operating costs andlimited portability due to the devices large power consumption, but alsocan become susceptible to premature failure due to the prolongedexposure to excessive heat.

SUMMARY OF THE INVENTION

The invention mitigates the above-described problems by providing highintensity lighting devices that employ a reflective member and a linearlight source, which by way of example can be a gas discharge lamp, suchas a fluorescent lamp, a mercury vapor lamp, or a neon lamp, or a linearincandescent lamp. The linear light source and reflective membertypically share a common axis that extends through their lengths.

More specifically, the present invention provides a lighting devicehaving a high luminous intensity. The lighting device comprises a linearlight source, a reflective member, and a translucent region. Preferably,the reflective member is shaped and sized to securely engage the linearlight source and the translucent region. which is typically transparent.In this design, the lighting device may be sealed from moisture andcontaminants and may be shielded from shock.

In one aspect of the invention, the reflective member comprises areflector having at least three polygonal-shaped sides. The reflector ispreferably located near the ends of the linear light source to directrays of light toward an intermediate translucent region. In alternativeembodiments, the reflective member may include more than one reflector,and each reflector may have a generally conical shape. The generallyconical shape may comprise circular, triangular, elliptical, parabolic,and other cross-sectional shapes to control the transmission pattern oflight. Preferably, when the reflector has circular cross-sections, itssmallest circular cross-section is positioned adjacent to an end of thelinear light source.

The above-described reflective member may comprise a specular or adiffuse reflector. Preferably, the reflective member further comprises acoating or reflective film, such as a silver reflective film. A coatingor reflective film offers the advantage of reflecting light with minimalabsorption which further increases the luminosity of the lightingdevice.

In another aspect of the invention, the translucent region has asubstantially cylindrical shape with a central axis typically coincidentwith the common axis of the linear light source and the reflectivemember. Alternatively, the translucent region can have a number ofcircumferential lengths or arcs. Lenses may also be used in this aspectof the invention so that rays of light incident on the translucentregion are refracted into an array of substantially parallel light raysemitted from the lighting device.

In yet another aspect of the invention, the translucent region maycomprise a plurality of prisms. In one exemplary embodiment, prismaticlight reflective material comprised of a plurality of substantiallyprism like members refract light at different angles to emit an array ofsubstantially parallel light rays from the lighting device. Thesetransmissive prisms refract light traveling in many different directionsto produce a highly luminous collimated array of light.

The reflective member has a substantially total internal reflectance(TIR) so that substantially all of the light produced by the lightsource is emitted from the lighting device through the translucentregion, and is preferably collimated by a lens unitarily formed orinterconnected with the translucent region. The axial length of thetranslucent region may comprise only a small portion of the total axiallength of the light source, such as on the order of one to seventy fivepercent, with ten to fifty percent being preferred. Nevertheless,substantially all of the light produced by the light source is emittedonly through the translucent region, resulting in a high intensitylighting device.

The disclosed devices consume little power and do not produce excessiveheat in comparison to known lighting devices. The reflective members canbe shaped and sized to a variety of linear light sources so that avariety of lights can be created from few parts, rendering a highlyadaptable technology that is economical to operate and inexpensive toconstruct. These features as well as other advantages of the inventionwill become apparent upon consideration of the following detaileddescription and accompanying drawings of the embodiments of theinvention described below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a preferred embodiment of the invention;

FIG. 2 is a side view of the preferred embodiment of FIG. 1 with asidewall partially removed;

FIG. 3 is a cross-sectional view of an alternate embodiment with a lens;

FIG. 4 is a cross-sectional view of a further embodiment of theinvention;

FIG. 5 is a cross-sectional view of a further embodiment of theinvention;

FIG. 6 is a cross-sectional view of a further embodiment of theinvention;

FIG. 7 is a cross-sectional view of a further embodiment of theinvention:

FIG. 8 is an exploded view of the prisms of the embodiment of FIG. 7;

FIG. 9 is a cross-sectional view of a further embodiment of theinvention partially illustrating the light paths of the reflected light;

FIG. 10 is a cross-sectional view of a further embodiment of theinvention;

FIG. 11 is a side view of a further embodiment of the invention;

FIG. 12 is an end view of the embodiment of FIG. 11; and

FIG. 13 is a top view of the embodiment of FIG. 11.

DETAILED DESCRIPTION

In the drawings, depicted elements are not necessarily drawn to scale,and alike and similar elements are designated by the same referencenumeral through several views.

FIGS. 1 and 2, illustrate the invention. The illustrated lighting device2 has a linear light source 4 and a reflective member 6 partiallydisposed within a substantially cylindrical housing 8. The housing 8 hasa first portion 10 and a second portion 12 separated by a translucentregion 14. The first portion 10 and second portion 12, in turn, form asealed cavity 16 with the translucent region 14 for receiving the linearlight source 4, the reflective member 6, a ballast type power supply ifa gas discharge lamp is used, and any other control circuitry.

The illustrated linear light source 4 is preferably a linear gasdischarge lamp that operates cooler and more efficiently thanincandescent lamps that emit light by heating a high resistant filament.However, a linear incandescent lamp may also be used. The inside of thegas discharge lamp is coated with phosphors, a substance that absorbsultraviolet radiation and reradiate the ultraviolet radiation as visiblelight. Colored phosphors are used to change the wavelength of the outputlight. A ballast is also used with gas discharge lamps to provide thevoltage needed to ionize the gas and thereby emit light.

A power supply 22, shown in FIG. 1, provides direct current to thelinear light source 4. A rectifier converts alternating current intodirect current, which is capacitively filtered. In one exemplaryembodiment, full-wave rectification converts one hundred and twentyvolts alternating current into twelve volts direct current to drive asmall fluorescent lamp ballast. Obviously, other stationary or portablepower supplies, power supply configurations, and operating voltages canalso be used. The power source should be designed to the requirements ofthe light source.

The reflective member 6, which is illustrated as a pair of hollowconical reflectors 24 and 26, is located within the first and secondportions 10 and 12 of the housing 8, respectively. In a preferredembodiment, the smallest circular cross-sections 28 and 30 of the twoconical reflectors 24 and 26 are positioned near the respective proximaland distal ends 32 and 34 of the linear light source 4. The diameters ofthese circular cross-sections 28 and 30 are sized to securely engage thelinear light source 4.

The reflective member 6 may have three or more polygonal shaped sidesthat are shaped as triangles or as other closed geometric shapes.Alternatively, the reflective member 6 may have one or more conicalsides.

Reflective member 6 can be made of metal, plastic, glass, or other rigidmaterials. Since these materials serve only to provide a desired formfor the reflective member 6 and provide physical support for areflective film or coating, the materials do not have to meet a highoptical quality standard.

A silver reflective film coupled to the interior surface 36 of thereflector 6 is used to reflect light toward the translucent region. Thereflective film manufactured by 3M Corporation of St. Paul Minn. underthe trademark “SILVERLUX” is used as the principal reflective material,although other reflective films and coatings may also be used. Thesefilms and coatings may be deposited, sprayed, or affixed by other knownmeans to the interior surface 36 of the reflective member 6.Alternatively, the reflective member 6 may comprise a polished surfaceor a naturally reflective surface such as a drawn aluminum alloy.

It can be seen in FIG. 2, that the longitudinal axis 38 of the linearlight source 4 and the axis 40 of the reflective member 6 aresubstantially coincident. This geometry causes light that would normallybe absorbed or propagated within the housing 8 to converge on thetranslucent region 14.

As shown in FIG. 2, the translucent region 14 has a substantiallycylindrical shape with a central axis 42 substantially coincident withthe longitudinal axis 38 of the linear light source 4. The translucentregion 14 may be made of glass, or a plastic material (i.e. acrylic,polycarbonate, silicone, etc.), or any other light transmissive materialand may include a lens 44 (shown in FIG. 3) that focuses rays of lighttoward an intended area. Alternatively, the translucent region 14 mayhave any of a number of axial lengths or arcs, and may, for example,comprise only a small axial length or arc of the housing 8. Preferably,the translucent region 14 is substantially cylindrical in shape and hasa constant radius of curvature.

A single lens 44 as shown in FIG. 3, or a compound lens (not shown) mayalso be used to improve the efficiency of the invention. As shown, thesingle lens 44 has two ground or polished surfaces, with the outersurface 46 being convex and the inner surface 48 being concave.

If desired, a number of other types of lenses may also be used. Lensesmade of prism-like members 50 also known as microprisms as shown inFIGS. 7 and 8, for example, may be used to refract the light that fallsincident on the translucent region 14. The prismatic light refractivematerial or film comprises a plurality of substantially prism likemembers 50 that refract light into a parallel array. These transmissiveprisms 50 refract light traveling in many different directions toproduce a highly luminous collimated array of light. Sheet like layersof microprisms manufactured by 3M Corporation of St. Paul Minn. underthe trademark “BEF” (Brightness Enhancing Film) may be used as theprincipal prism lens.

It should be noted that the invention is not limited to the illustrateddimensions, combinations of geometric shapes, or to the geometric shapesof the reflective members 6 shown in the accompanying figures. Thus, thesubstantially-conical shapes of the reflective members 6 shown in FIGS.5 and 8, the profiles of the reflective member 6 shown in FIG. 6, thecombination of geometric shapes that comprise the reflective member 6,such as a substantially hollow conical and a plane reflectors 52 and 54of FIG. 10, and the varying lengths of the reflective members 6 shown inthe other figures, illustrate only a few of the many forms that theinvention can take. As shown in FIGS. 11 and 13, the reflective member 6may also comprise any substantially enclosed reflective housing 56.

The curvlineal reflective housing 56 illustrated in FIGS. 11-13 comprisetwo portions 58 and 60. A concave recess 62 extending along the lengthof the reflective housing 56 forms one portion of the housing whileoppositely sloped walls 64 and 66 contiguous with a pair of curvedportions 68 and 70 partially form an opposite portion of the housing 56.The reflective housing 56 substantially encloses the linear light source4, such that the translucent region 14 positioned intermediate of theproximal and distal ends 32 and 34 of the linear light source 4 emitssubstantially all of the light produced by the linear light source 4. Asin many of the previously described embodiments, the longitudinal axisof the housing 56 is substantially coincident with the axis of thelinear light source 4.

Each reflective member 6 or portion shown in each of the figures canvary from the illustrations. These reflective members 6 and variationsthereof, illustrate the structure for performing the function ofdirecting light from the linear light source 4 toward the translucentregion 14.

While it is not intended that the reflective member 6 be limited to anyparticular type of reflector, the preferred embodiments of the inventionemployed specular and diffuse reflectors. As shown in FIG. 9, thereflective member 6 provides a number of advantages including reflectingsubstantially all of the light emitted from the linear light source 4 tothe translucent region 14.

In the normal application of the invention, the translucent region 14can be positioned anywhere from the proximal to the distal ends 32 and34 of the linear light source 4 wherein the axial length of thetranslucent region can be substantially between one to fifty percent ofthe axial length of the linear light source 4. The circumferentiallength or arc of the translucent region 14 can also vary anywhere fromallowing up to three hundred and sixty degrees of output to an arc thatallows less than three hundred and sixty degrees of output.

Given that the luminous intensity of the invention is achieved byinternally reflecting much of the linear light source's output fromwithin a housing through only a relatively small translucent region, theinvention encompasses any structure that can achieve that function. Forexample, the linear light source 4 and reflective member 6 axis 38 and40 do not have to be coincident nor do any of the disclosed axis 38, 40,and 42 have to be coincident.

The descriptions set forth in Table 1 below are provided to illustrate afew of the many forms that the invention may take along with theirrespective properties. These examples should not be considered limiting.

TABLE 1 Example 1 16,500 Candela* Luminous intensity of linear Iightsource (fluorescent tube) Luminous intensity of the device output 40,950Candela Illuminated length of linear light source 170 MillimetersTranslucent region longitudinal length 35 Millimeters Current rating 10Milliamperes Housing diameter 80 Millimeters Example 2 Luminousintensity of linear light source 13,470 Candela (fluorescent tube)Luminous intensity of the device output 28,910 Candela Illuminatedlength of linear light source 100 Millimeters Translucent regionlongitudinal length 30 Millimeters Current rating 5 Milliamperes Housingdiameter 25 Millimeters *A unit of luminous intensity equal to 1/60 ofthe luminous intensity per square centimeter of a blackbody radiating atthe temperature of solidification of platinum (2,046° K.).

The foregoing detailed description describes only a few of the manyforms that the present invention can take, and should therefore be takenas illustrative rather than limiting. It is only the following claims,including all equivalents that are intended to define the scope of theinvention.

What is claimed is:
 1. A lighting device, comprising: a linear lightsource having a longitudinal axis, and having a first end and a secondend defining a light-emitting length therebetween; a translucent regionpositioned substantially intermediate said first and said second ends,said translucent region having a length substantially less than thelight-emitting length; and a reflective member having an axissubstantially coincident with said longitudinal axis, said reflectivemember positioned intermediate said first end and said translucentregion to direct light emitted from a substantial portion of said linearlight source toward said translucent region.
 2. The lighting device ofclaim 1, wherein said linear light source comprises a gas dischargelamp.
 3. The lighting device of claim 1, wherein said translucent regioncomprises a lens.
 4. The lighting device of claim 3, wherein said lenscomprises at least one of a convex and a concave surface.
 5. Thelighting device of claim 1, wherein said translucent region comprises aplurality of prisms.
 6. The lighting device of claim 1, wherein saidreflective member is shaped and sized to securely engage said linearlight source and said translucent region.
 7. The lighting device ofclaim 1, wherein said reflective member comprises a reflector having atleast three polygonal sides.
 8. The lighting device of claim 1, whereinsaid reflective member comprises more than one reflector having at leastthree polygonal sides.
 9. The lighting device of claim 1, wherein saidreflective member comprises at least one substantially conical shapedreflector.
 10. The lighting device of claim 9, wherein said at least onesubstantially conical shaped reflector includes two conical-shapedreflectors of different corresponding diameters and the smaller of saidconical shaped reflectors is oriented toward an end of said linear lightsource.
 11. The lighting device of claim 1, wherein said reflectivemember comprises more than one substantially conical shaped reflectorhaving circular cross-sections in which the smallest of each of saidcircular cross-sections of each of said reflectors is oriented toward anend of said linear light source.
 12. The lighting device of claim 9,wherein said substantially conical shaped reflector has a substantiallyright circular cone shape.
 13. The lighting device of claim 10, whereineach of said substantially conical shaped reflectors has a differentaxial length.
 14. The lighting device of claim 1, wherein saidtranslucent region has a substantially cylindrical shape and a centralaxis coincident with said longitudinal axis.
 15. The lighting device ofclaim 1, wherein said translucent region emits a substantiallycollimated beam of light.
 16. The lighting device of claim 1, whereinsaid reflective member comprises a specular reflector.
 17. The lightingdevice of claim 1, wherein said reflective member comprises a diffusereflector.
 18. The lighting device of claim 1, wherein said reflectivemember comprises a reflective coating affixed to a surface.
 19. Thelighting device of claim 1, wherein said reflective member includes asilver reflective film.
 20. The lighting device of claim 1, wherein saidreflective member comprises a metal reflector.
 21. The lighting deviceof claim 1, wherein said reflective member comprises a reflective film.22. The lighting device of claim 1, wherein said translucent region hasan arc of 360 degrees.
 23. The lighting device of claim 1, wherein saidtranslucent region has an arc of less than 360 degrees.
 24. The lightingdevice of claim 1, wherein the length of the translucent region isapproximately fifty percent of the light-emitting length.
 25. Thelighting device of claim 1, wherein the length of the translucent regionis between about one percent and about fifty percent of thelight-emitting length.
 26. The lighting device of claim 1, furthercomprising a second reflective member positioned intermediate saidsecond end and said translucent region to direct light emitted from saidlinear light source toward said translucent region.
 27. The lightingdevice of claim 26, wherein the translucent region, the reflectivemember, and the second reflective member together extend substantiallythe full light-emitting length.
 28. A lighting device, comprising: alinear light source having a first end and a second end; a translucentregion positioned substantially intermediate said first and said secondends, said translucent region completely surrounding a portion of thelinear light source; and means for directing light emitted from saidlinear light source toward said translucent region, said directing meanshaving a common longitudinal axis with said linear light source, whereinsaid directing means comprises at least one substantially conical shapedreflector.
 29. The lighting device of claim 28, wherein said linearlight source comprises a gas discharge lamp.
 30. The lighting device ofclaim 28, wherein said translucent region comprises a lens.
 31. Thelighting device of claim 30, wherein said lens comprises at least one ofa convex and a concave surface.
 32. The lighting device of claim 28,wherein said translucent region comprises a plurality of prisms.
 33. Thelighting device of claim 28, wherein said directing means is shaped andsized to securely engage said linear light source and said translucentregion.
 34. The lighting device of claim 28, wherein said directingmeans comprises more than one reflector having at least three polygonalsides.
 35. The lighting device of claim 28, wherein said at least onesubstantially conical shaped reflector includes two conical-shapedreflectors of different corresponding diameters and the smaller of saidconical shaped reflectors is orientated toward an end of said linearlight source.
 36. The lighting device of claim 35, wherein each of saidsubstantially conical shaped reflectors has a different axial length.37. The lighting device of claim 28, wherein said directing meanscomprises more than one substantially conical shaped reflector havingcircular cross-sections in which the smallest of each of said circularcross-sections of each of said reflectors is orientated toward an end ofsaid linear light source.
 38. The lighting device of claim 28, whereinsaid substantially conical shaped reflector has a substantially rightcircular cone shape.
 39. The lighting device of claim 28, wherein saidtranslucent region has a substantially cylindrical shape and a centralaxis coincident with said longitudinal axis.
 40. The lighting device ofclaim 28, wherein said translucent region emits a substantiallycollimated beam of light.
 41. The lighting device of claim 28, whereinsaid directing means comprises a specular reflector.
 42. The lightingdevice of claim 28, wherein said directing means comprises a diffusereflector.
 43. The lighting device of claim 28, wherein said directingmeans comprises a reflective coating affixed to a surface.
 44. Thelighting device of claim 28, wherein said directing means includes asilver reflective film.
 45. The lighting device of claim 28, whereinsaid directing means comprises a metal reflector.
 46. The lightingdevice of claim 28, wherein said directing means includes a reflectivefilm.
 47. The lighting device of claim 28, wherein said directing meanscomprises a reflective coating coupled to a surface.
 48. The lightingdevice of claim 28, wherein said directing means comprises a metalreflector.
 49. The lighting device of claim 28, wherein the linear lightsource defines a light-emitting length that extends from the first endto the second end, and the translucent region defines a length, andwherein the length of the translucent region is approximately fiftypercent of the light-emitting length.
 50. The lighting device of claim28, wherein the linear light source defines a light-emitting length thatextends from the first end to the second end, and the translucent regiondefines a length, and wherein the length of the translucent region isbetween about one percent and about fifty percent of the light-emittinglength.
 51. A lighting device comprising: a linear light source having afirst end and a second end; a translucent region positionedsubstantially intermediate said first and said second ends, saidtranslucent region completely surrounding a portion of the linear lightsource; and means for directing light emitted from said linear lightsource toward said translucent region, said directing means having acommon longitudinal axis with said linear light source, wherein saiddirecting means comprises a reflector having at least three polygonalsides.